**Core Concept:**
The inguinal canal is a transversal, fibrous tunnel located in the abdominal wall, connecting the deep inguinal ring to the pubic symphysis. It serves as a passage for various structures, such as spermatic cord/round ligament in males and the round ligament of uterus in females, as well as the internal iliac artery, vein, and lymphatic vessels.

**Why the Correct Answer is Right:**
The correct answer, **C. Round ligament of uterus**, is included in the inguinal canal in females. The round ligament is a thin, tendinous cord that connects the uterus to the iliacus muscle, passing through the inguinal canal as it extends towards the labia majora.

In contrast, option A (spermatic cord/round ligament in males) and option D (internal iliac artery, vein, and lymphatic vessels) are not part of the human female's inguinal canal contents, as they are specific to males.

**Why Each Wrong Option is Incorrect:**

A. **Spermatic cord/round ligament in males (Option A)**: Although this structure is present in males, it is not part of the inguinal canal contents in females.

B. **Internal iliac artery, vein, and lymphatic vessels (Option D)**: These structures are specific to males and do not belong in the inguinal canal of females.

**Clinical Pearl:**

The inguinal canal is a crucial anatomical landmark to understand during surgical procedures, such as laparoscopic or open inguinal hernia repair. Familiarizing yourself with the contents of the inguinal canal will aid in preventing iatrogenic injury to the spermatic cord or round ligament during surgeries involving the inguinal region.